Science Alert  October 31, 2020 Every 200,000 to 300,000 years, Earth’s magnetic poles reverse. The last reversal was unusual because for some reason, the poles have remained oriented the way they are now for about three-quarters of a million years. Researchers in Japan collected new samples and conducted paleo- and rock-magnetic analyses of samples from the Chiba composite section which is considered to contain the most detailed marine sedimentary record of the Matuyama-Brunhes geomagnetic reversal. It provides the most reliable chronostratigraphic framework of the time period around the Brunhes-Matuyama reversal. According to their study it took about 20,000 years, including […]